1. Field of the Invention
The present invention relates to a method for determining a condition of a road surface on which a vehicle travels, and more particularly to a method for determining a road surface condition using data of a time-series waveform of tire vibration only.
2. Description of the Related Art
There have been conventional methods for determining a road surface condition using only the data of a time-series waveform of tire vibration during vehicular travel. Used in one of such methods for determining a road surface condition are kernel functions calculated from feature vectors for respective time windows calculated from the time-series waveform extracted by windowing the time-series waveform of tire vibration and road surface feature vectors, which are feature vectors for the respective time windows calculated from the time-series waveform of tire vibration having been determined in advance for distinctive road surface conditions (see Patent Document 1, for instance).